ME环境变量
echo "my home dir is $HOME"

# 2. 输出MM-DD-YYYY格式的日期
echo "Today is $(date +%m-%d-%Y)"

# 3. 定义函数print_myinfo，接收班级、姓名、学号参数并打印
print_myinfo() {
    echo "我是【$1】的【$2】，我的学号是【$3】"
}

# 调用函数，传入命令行参数（$1=班级，$2=姓名，$3=学号）
print_myinfo "$1" "$2" "$3"

